WO2016167152A1

WO2016167152A1 - Gas-barrier plastic molded product and method for manufacturing same

Info

Publication number: WO2016167152A1
Application number: PCT/JP2016/061070
Authority: WO
Inventors: 博康田渕
Original assignee: キリン株式会社
Priority date: 2015-04-17
Filing date: 2016-04-05
Publication date: 2016-10-20
Also published as: KR20170138476A; JP6474673B2; EP3284846A1; US10487397B2; US20180127872A1; CN107429392A; JP2016204685A; CN107429392B; TW201641732A; EP3284846B1; PH12017501752A1; TWI686497B; EP3284846A4; AU2016248605A1; SG11201708290QA; MY186446A

Abstract

The purpose of the present invention is to provide a gas-barrier plastic molded product having superior gas-barrier properties and transparency, and a method for manufacturing the same. A gas-barrier plastic molded product 90 according to the present invention is provided with a plastic molded product 91 and a gas-barrier thin-film 92 provided on the surface of the plastic molded product 91, wherein the gas-barrier thin-film 92 contains silicon (Si), carbon (C), and oxygen (O) as constituent elements, and when carrying out X-ray electron spectrometry under condition (1), the gas-barrier thin-film 92 has a region in which the main peak is observed in a peak appearance position of the Si-C binding energy. Condition (1): measurement range is 95-105 eV.

Description

Gas barrier plastic molded body and method for producing the same

The present invention relates to a gas barrier plastic molding and a method for producing the same.

Conventionally, a heating element CVD method is known as a technique for forming a thin film having gas barrier properties (hereinafter sometimes referred to as a gas barrier thin film). The heating element CVD method is also referred to as a Cat-CVD method or a hot wire CVD method, which decomposes by bringing a raw material gas into contact with a heated heating element and undergoes a reaction process directly or in a gas phase. This is a method of depositing as a thin film on the surface of a plastic molded body (see, for example, Patent Document 1).

WO2012 / 091097 WO2013 / 099960

In addition to high gas barrier properties, plastics may require high transparency. The method described in Patent Document 1 is excellent in gas barrier properties but lacks transparency.

An object of the present invention is to provide a gas barrier plastic molded article excellent in gas barrier properties and transparency and a method for producing the same.

The gas barrier plastic molded article according to the present invention is a gas barrier plastic molded article comprising a plastic molded article and a gas barrier thin film provided on the surface of the plastic molded article, wherein the gas barrier thin film comprises silicon (Si) as a constituent element, It contains carbon (C) and oxygen (O), and when X-ray electron spectroscopy analysis is performed under the condition (1), it has a region where a main peak is observed at the peak appearance position of the bond energy of Si—C. Features.
Condition (1) The measurement range is 95 to 105 eV.

In the gas barrier plastic molded article according to the present invention, the gas barrier thin film has a gradient composition in the depth direction, the gas barrier thin film is divided into two equal parts in the depth direction, and the side opposite to the plastic molded article is the upper layer. When the plastic molding side is the lower layer, the C content represented by (Equation 1) in the upper layer is preferably higher than the Si content represented by (Equation 2) in the upper layer.
(Equation 1) C content [%] = {(C content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 1, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.
(Expression 2) Si content [%] = {(Si content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Formula 2, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.

In the gas barrier plastic molded article according to the present invention, it is preferable that the O content represented by (Equation 3) in the upper layer is lower than the Si content in the upper layer.
(Equation 3) O content [%] = {(O content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 3, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.

In the gas barrier plastic molded article according to the present invention, the gas barrier thin film has a gradient composition in the depth direction, the gas barrier thin film is divided into two equal parts in the depth direction, and the side opposite to the plastic molded article is the upper layer. When the plastic molding side is the lower layer, the C content represented by (Equation 1) in the lower layer is preferably higher than the O content represented by (Equation 3) in the lower layer. By making C content rate higher than O content rate in a lower layer, the adhesiveness of a thin film and a plastic molding can be improved.
(Equation 1) C content [%] = {(C content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 1, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.
(Equation 3) O content [%] = {(O content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 3, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.

The method for producing a gas barrier plastic molding according to the present invention includes an evacuation step in which the inside of a vacuum chamber is evacuated to adjust the inside of the vacuum chamber to an initial pressure P ₀ or lower, and the pressure in the vacuum chamber is set to P ₀ or lower. When the heating element having a tantalum carbide phase that is conditioned and disposed in the vacuum chamber is not heated, a silicon-containing hydrocarbon gas is introduced into the vacuum chamber to reduce the pressure in the vacuum chamber. _A gas barrier thin film on the surface of the plastic molded body accommodated in the vacuum chamber by heating the heating element while continuously introducing the silicon-containing hydrocarbon gas into the vacuum chamber. And a film forming step for forming the film.

In the method for manufacturing a gas barrier plastic molded body according to the present invention, in the preparation step, after adjusting the pressure in the vacuum chamber to said P _0, reaches the pressure in the vacuum chamber at a higher pressure P _A from the P ₀ It is allowed, in the film forming step, it is preferable to reach a higher pressure P _B of the pressure from the P _a of the vacuum chamber.

In the method for producing a gas barrier plastic molding according to the present invention, (P _B -P _A ) / P ₀ is preferably 0.11 or more.

The present invention can provide a gas barrier plastic molded article excellent in gas barrier properties and transparency and a method for producing the same.

It is sectional drawing which shows an example of the gas barrier plastic molding which concerns on this embodiment. It is the schematic which shows an example of the conventional film-forming apparatus. It is the conceptual diagram which showed an example of the pressure change in the vacuum chamber and the temperature change of a heat generating body in the manufacturing method which concerns on this embodiment. It is the narrow scan spectrum of Si2p which analyzed the thin film surface by conditions (1), (a) is the thin film of Example 1, (b) is the thin film of the comparative example 1. FIG. It is a depth profile of Example 1. It is a depth profile of the comparative example 1.

Next, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions. As long as the effect of the present invention is exhibited, the embodiment may be variously modified.

FIG. 1 is a cross-sectional view showing an example of a gas barrier plastic molded article according to this embodiment. The gas barrier plastic molded body 90 according to the present embodiment is a gas barrier plastic molded body including a plastic molded body 91 and a gas barrier thin film 92 provided on the surface of the plastic molded body 91. The gas barrier thin film 92 includes silicon as a constituent element. (Si), carbon (C) and oxygen (O), and when X-ray electron spectroscopy analysis is performed under the condition (1), a region where a main peak is observed at the peak appearance position of Si—C bond energy Have
Condition (1) The measurement range is 95 to 105 eV.

Examples of the resin constituting the plastic molded body 91 include polyethylene terephthalate resin (PET), polybutylene terephthalate resin, polyethylene naphthalate resin, polyethylene resin, polypropylene resin (PP), and cycloolefin copolymer resin (COC, cyclic olefin copolymer). , Ionomer resin, poly-4-methylpentene-1 resin, polymethyl methacrylate resin, polystyrene resin, ethylene-vinyl alcohol copolymer resin, acrylonitrile resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyamide resin, polyamideimide resin Polyacetal resin, polycarbonate resin, polysulfone resin, tetrafluoroethylene resin, acrylonitrile-styrene resin, or acrylonitrile-butadiene-styrene resin That. One of these may be used as a single layer, or two or more may be used as a laminate, but a single layer is preferable in terms of productivity. The type of resin is more preferably PET.

The gas barrier plastic molded body 90 according to the present embodiment includes a form in which the plastic molded body 91 is a container, a film, or a sheet. The shape can be appropriately set according to the purpose and application, and is not particularly limited. The container includes a container that is used with a lid, a stopper, or a seal, or a container that is used without being used. The size of the opening can be appropriately set according to the contents. The plastic container includes a plastic container having a predetermined thickness having moderate rigidity and a plastic container formed by a sheet material having no rigidity. The present invention is not limited to the manufacturing method of the container. The contents are, for example, beverages such as water, tea beverages, soft drinks, carbonated beverages or fruit juice beverages, or liquid, viscous, powder or solid foods. Further, the container may be either a returnable container or a one-way container. The film or sheet includes a long sheet or cut sheet. It does not matter whether the film or sheet is stretched or unstretched. The present invention is not limited to the method for manufacturing the plastic molded body 91.

The thickness of the plastic molded body 91 can be appropriately set according to the purpose and application, and is not particularly limited. When the plastic molded body 91 is, for example, a container such as a beverage bottle, the thickness of the bottle is preferably 50 to 500 μm, more preferably 100 to 350 μm. When the plastic molded body 91 is a film constituting a packaging bag, the thickness of the film is preferably 3 to 300 μm, more preferably 10 to 100 μm. When the plastic molded body 91 is a substrate of a flat panel display such as electronic paper or organic EL, the thickness of the film is preferably 25 to 200 μm, more preferably 50 to 100 μm. When the plastic molded body 91 is a sheet for forming a container, the thickness of the sheet is preferably 50 to 500 μm, more preferably 100 to 350 μm. When the plastic molded body 91 is a container, the gas barrier thin film 92 is provided on one or both of the inner wall surface and the outer wall surface. Further, when the plastic molded body 91 is a film, the gas barrier thin film 92 is provided on one side or both sides.

The gas barrier thin film 92 contains silicon (Si), carbon (C), and oxygen (O) as constituent elements, and when the X-ray electron spectroscopic analysis is performed under the condition (1), the peak appearance position of the bond energy of Si—C And has a region where the main peak is observed.
Condition (1) The measurement range is 95 to 105 eV.

By having a region where the main peak is observed at the peak appearance position of the Si—C bond energy, the gas barrier thin film 92 is a thin film having excellent transparency. In the present specification, the main peak means a peak having the highest intensity among peaks observed by separating the peaks in the condition (1).

The bonding mode of the compound contained in the gas barrier thin film 92 is, for example, Si—Si bond, Si—H bond, Si—O bond, C—H bond, C—C bond, C—O other than Si—C bond. A bond, C═O bond, Si—O—C bond, C—O—C bond, O—C—O bond or O═C—O bond.

In the gas barrier plastic molded body according to the present embodiment, when the gas barrier thin film 92 is subjected to X-ray electron spectroscopy analysis under the condition (1), a peak observed at the peak appearance position of the Si—C bond energy is a Si—Si bond. It is preferably larger than the peak observed at the energy peak appearance position. Thereby, the transparency can be further enhanced.

In the gas barrier plastic molded body 90 according to the present embodiment, the gas barrier thin film has a gradient composition in the depth direction, the gas barrier thin film 92 is divided into two equal parts in the depth direction D, and is opposite to the plastic molded body 91. Is the upper layer 92a and the plastic molded body 91 side is the lower layer 92b, the C content represented by (Equation 1) in the upper layer 92a is higher than the Si content represented by (Equation 2) in the upper layer 92a. (Condition 1) is preferable. Thereby, the transparency can be further enhanced.
(Equation 1) C content [%] = {(C content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 1, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.
(Expression 2) Si content [%] = {(Si content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Formula 2, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.

The upper layer 92a is a portion having a thickness T / 2 [nm] from the surface 92s of the gas barrier thin film 92 when the thickness of the gas barrier thin film 92 is T [nm]. The lower layer 92b is a portion between the upper layer 92a and the plastic molded body 91, and is a portion having a thickness T / 2 [nm] from the interface between the gas barrier thin film 92 and the plastic molded body 91.

In the gas barrier plastic molded body 90 according to this embodiment, the film thickness T of the gas barrier thin film 92 is preferably 5 nm or more. More preferably, it is 10 nm or more. If it is less than 5 nm, gas barrier properties may be insufficient. The upper limit value of the thickness of the gas barrier thin film 92 is preferably 200 nm. More preferably, it is 100 nm. If the thickness of the gas barrier thin film 92 exceeds 200 nm, cracks are likely to occur due to internal stress.

The gas barrier thin film 92 has a gradient composition in the depth direction D. The depth direction D refers to a direction from the surface 92s of the gas barrier thin film 92 toward the plastic molded body 91 as shown in FIG. The graded composition refers to a composition in which the content of at least one of Si, O, or C changes continuously or stepwise in the depth direction D. The fact that the gas barrier thin film 92 has a gradient composition in the depth direction D does not mean that the upper layer 92a and the lower layer 92b have independent gradient compositions, but the upper layer 92a and the lower layer 92b have a clear boundary between them. It means having a series of gradient compositions. The gradient composition may be inclined over the entire area of the upper layer 92a and the lower layer 92b, or may have a portion that is not inclined in a part of the upper layer 92a or the lower layer 92b. It can be confirmed that the gas barrier thin film 92 has a gradient composition in the depth direction D by measuring the depth profile while performing argon ion etching in the XPS analysis.

In the gas barrier plastic molded body 90 according to the present embodiment, the O content represented by (Equation 3) in the upper layer 92a is lower than the Si content represented by (Equation 2) in the upper layer 92a (Condition 2). It is preferable. By having Condition 2 in addition to Condition 1, the upper layer 92a has the highest C content, then the Si content and the O content, and the transparency can be further enhanced.
(Equation 3) O content [%] = {(O content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 3, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.

The C content of the upper layer 92a is preferably 40 to 60%, more preferably 43 to 58%. The Si content of the upper layer 92a is preferably 20 to 40%, and more preferably 25 to 38%. The O content of the upper layer 92a is preferably 5 to 30%, more preferably 7 to 28%. The Si content, C content, or O content can be measured, for example, by XPS analysis of the gas barrier thin film 92.

In the gas barrier plastic molded article according to the present embodiment, the C content represented by (Equation 1) in the lower layer 92b is higher than the O content represented by (Equation 3) in the lower layer 92b (Condition 3). Is preferred. By making the C content higher than the O content in the lower layer 92b, the adhesion between the thin film and the plastic molded body can be increased.

The relationship between the Si content, the O content, and the C content in the conditions 1 to 3 indicates that the depth profile of the gas barrier thin film has an extreme value in the upper and lower layers of the Si profile, O profile, and C profile. One profile having one by one is selected, and a determination is made based on the level of Si, O, or C atomic concentration at each extreme value of the upper or lower layer of the selected profile (Criteria 1). In the criterion 1, when there are a plurality of profiles each having one extreme value in the upper layer and the lower layer, the priority order to be selected is the order of the O profile, the C profile, and the Si profile. Alternatively, the high / low relationship between the Si content, the O content, and the C content in the conditions 1 to 3 is determined by the high / low relationship between the Si content, the O content, and the C content in the entire upper layer or the entire lower layer (determination) Standard 2). In criterion 2, the Si content, O content, and C content in the entire upper layer or lower layer are, for example, integrated atomic concentrations in the upper layer or lower layer of each of the Si, O, and C profiles in the depth profile of the gas barrier thin film. It can be obtained as a value. In the present embodiment, it is determined that the condition 1 is satisfied when the condition 1 is satisfied in at least one of the determination criterion 1 and the determination criterion 2. Naturally, it is determined that the condition 1 is satisfied even when the condition 1 is satisfied in both the determination criterion 1 and the determination criterion 2. As for condition 2 or condition 3, whether condition 2 or condition 3 is satisfied is determined in the same manner as condition 1.

The gas barrier thin film 92 may contain other elements in addition to Si, C and O. The other element is, for example, a metal element derived from a heating element such as tantalum (Ta), hydrogen (H), or nitrogen (N).

The gas barrier thin film 92 is preferably substantially colorless and transparent. In the present specification, “substantially colorless and transparent” means that the b ^* value is 2.0 or less, using the degree of coloration b ^*, which is the color difference in JIS K 7105-1981 “Testing methods for optical properties of plastics” as an index. Say things. The b ^* value is more preferably 1.7 or less. The b ^* value can be obtained by Equation 4. In Equation 4, Y or Z is a tristimulus value. Further, the correlation between the b ^* value and visual observation in the present invention is as shown in Table 1.

The gas barrier plastic molded body 90 according to this embodiment preferably has a barrier property improvement rate (Barrier Improvement Factor, hereinafter referred to as BIF) obtained by Equation 5 of 5 or more. More preferably, it is 10 or more. As a specific example, in a 500 ml PET bottle (height 133 mm, trunk outer diameter 64 mm, mouth outer diameter 24.9 mm, mouth inner diameter 21.4 mm, wall thickness 300 μm, resin amount 29 g), the oxygen permeability is set to 0.1. 0070 cc / container / day or less. In a 720 ml PET bottle, the oxygen permeability can be 0.0098 cc / container / day or less.
(Equation 5) BIF = [Oxygen permeability of plastic molding without thin film] / [Oxygen permeability of gas barrier plastic molding]

The gas barrier plastic molding according to the present embodiment can be manufactured by a conventional film forming apparatus as shown in FIG. The film forming apparatus shown in FIG. 2 is the apparatus shown in FIG. 3 of WO2013 / 099960 (Patent Document 2), and details of the apparatus are described in WO2013 / 099960. Here, the film forming apparatus will be briefly described with reference to FIG.

The film forming apparatus includes a dedicated film forming chamber 31 for forming a plastic molded body (plastic bottle in FIG. 2) 4 and a loading / unloading chamber 32 for loading and unloading the plastic molded body 4. A gate valve 33 is provided between the membrane dedicated chamber 31 and the entrance / exit chamber 32.

The film formation dedicated chamber 31 has a reaction chamber for forming a thin film on the surface of the plastic molded body 4 therein. A heating element 42 and a source gas supply pipe (not shown) are arranged in the reaction chamber. The reaction chamber can be evacuated by the vacuum pump VP1.

The entrance / exit chamber 32 has a standby chamber for waiting for the plastic molded body 4 before film formation therein. The waiting room can be evacuated by the vacuum pump VP2. The entrance / exit chamber 32 has an open / close gate 56. By opening the open / close gate 56, the plastic molded body 4 before film formation can be introduced into the standby chamber, and the plastic molded body 4 after film formation can be taken out from the standby chamber.

The gate valve 33 is a partition between the film formation dedicated chamber 31 and the entrance / exit chamber 32.

Next, with reference to FIG. 2, a method for producing a gas barrier plastic molded body according to this embodiment will be described by taking as an example a case where a gas barrier thin film is formed on the inner surface of a plastic bottle as the plastic molded body 4. The present invention is not limited to an apparatus, and for example, as shown in FIG. 2 of Patent Document 1, an apparatus having only one chamber may be used.

The method for producing a gas barrier plastic molded body according to the first embodiment includes an evacuation step of evacuating the inside of the vacuum chamber 31 (deposition chamber for film formation in FIG. 2) to adjust the inside of the vacuum chamber 31 to an initial pressure P ₀ or less. When the pressure in the vacuum chamber 31 is adjusted to P ₀ or less and the heating element 42 having a tantalum carbide phase disposed in the vacuum chamber 31 is not heated, the silicon-containing hydrocarbon gas is removed from the vacuum chamber 31. And the heating element 42 is heated while the silicon-containing hydrocarbon gas is continuously introduced into the vacuum chamber 31 and introduced into the vacuum chamber 31 to adjust the pressure in the vacuum chamber 31 to P _0. A film forming step of forming a gas barrier thin film on the surface of the plastic molded body 4 (plastic bottle in FIG. 2).

In the exhaust process, the gate valve 33 and the open / close gate 56 are closed. By operating the vacuum pump VP1, to evacuate the air in the vacuum chamber (film formation only chamber) 31, to the inside of the vacuum chamber 31 below the initial pressure P _0. The initial pressure P ₀ is preferably 1.5 Pa, and more preferably 1.0 Pa. Further, the lower limit of the pressure in the vacuum chamber 31 in the exhaust process is not particularly limited.

In the exhaust process, it is preferable that the vacuum pump VP2 is operated in parallel with the exhaust in the vacuum chamber 31 to exhaust the air in the access chamber 32. At this time, the pressure in the entrance / exit chamber 32 may be higher or lower than the pressure in the vacuum chamber 31.

In the apparatus shown in FIG. 2, the preparation step is preferably started when the gate valve 33 is opened and the vacuum chamber 31 and the entrance / exit chamber 32 communicate with each other. When the gate valve 33 is opened, the pressure in the vacuum chamber 31 and the pressure in the access chamber 32 become equal.

In the preparation step, silicon-containing hydrocarbon gas is introduced while the vacuum chamber 31 is evacuated to adjust the pressure in the vacuum chamber 31 to P ₀ . When silicon-containing hydrocarbon gas is introduced, the pressure in the vacuum chamber 31 increases rapidly, and the pressure in the vacuum chamber 31 may greatly exceed P ₀ (for example, exceed P _B ) in the initial stage of the preparation process. In this case, by evacuating the vacuum chamber 31, it is preferable to adjust so as not the pressure in the vacuum chamber 31, for example, in large pressure exceeding P _B. Further, the pressure in the vacuum chamber 31 may be adjusted to be less than P ₀ in the evacuation process so that the pressure in the vacuum chamber 31 does not become a large pressure exceeding, for example, P _B in the preparation process. The pressure in the vacuum chamber 31 is adjusted by controlling the flow rate of the silicon-containing hydrocarbon gas, for example. By using silicon-containing hydrocarbon gas, a substantially colorless and transparent gas barrier thin film can be formed. The silicon-containing hydrocarbon gas is a gas used as a raw material gas in the film forming process. For example, silicon tetrachloride, hexamethyldisilane, vinyltrimethylsilane, methylsilane, dimethylsilane, trimethylsilane, vinylsilane, diethylsilane, propylsilane, Organosilane compounds such as phenylsilane, methyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane or methyltriethoxysilane, octamethylcyclotetra Organosiloxane compounds such as siloxane, 1,1,3,3-tetramethyldisiloxane, tetraethoxysilane or hexamethyldisiloxane, or hexamethylsilaza Organic silazane compounds such as are used. In addition to these materials, aminosilane and the like are also used. Among these silicon-containing hydrocarbons, an organic silane compound that does not contain oxygen or nitrogen as a constituent element is preferable. In terms of ease of use, the constituent element has a higher carbon ratio than silicon and can be treated as a gas at normal temperature and pressure. Vinylsilane, dimethylsilane, trimethylsilane or tetramethylsilane is particularly preferred.

Before the preparation step is completed, it is preferable to lower the plastic molded body 4 disposed in the entrance / exit chamber 32 to reach a predetermined position near the heating element 42. The preparation process is completed when the inside of the vacuum chamber 31 reaches a predetermined pressure. Predetermined pressure is preferably higher pressure P _A from P _0. Further, when the film reaches a predetermined position in the vicinity of the heating element 42, for example, when forming a film on the inner surface of the plastic bottle as the plastic molded body 4, as shown in FIG. 2, the heating element 42 and the source gas supply pipe (Not shown) is the state inserted in the plastic bottle.

In the film forming step, the heating element 42 is heated while continuously introducing the silicon-containing hydrocarbon gas into the vacuum chamber 31 to form a gas barrier thin film on the surface of the plastic molded body 4.

The heating element 42 is heated by energization, for example. The heating element 42 has a tantalum carbide phase. By using the heating element 42 having a tantalum carbide phase, a substantially colorless and transparent gas barrier thin film can be formed. The tantalum carbide phase is, for example, a carbide obtained by carbonizing tantalum, a tantalum-based alloy, or tantalum or a tantalum-based alloy containing an additive. Moreover, the tantalum carbide phase may contain, for example, Ta ₂ C and TaC. The tantalum carbide phase may be present throughout the heating element 42 or may be present in a portion of the heating element 42. The form in which the tantalum carbide phase is present in a part of the heating element 42 is, for example, a form in which the heating element 42 has a center portion and a peripheral portion and the tantalum carbide phase exists only in the peripheral portion of the heating element 42. At this time, the central part preferably has a metal tantalum phase. The heating temperature of the heating element 42 is not particularly limited, but is preferably 1600 ° C. or higher and lower than 2400 ° C., more preferably 1850 ° C. or higher and lower than 2350 ° C., and further preferably 2000 ° C. or higher and 2200 ° C. or lower. .

In the first embodiment, the heating element 42 is heated for the first time in the film forming process, and the heating element 42 is not heated in the exhaust process and the preparation process. Before the preparation process is completed, the only gas remaining in the vacuum chamber 31 is air, and when the heating element 42 is heated in such an atmosphere, the heating element 42 is likely to be oxidized and deteriorated. Further, in order to make the heating element CVD method available in an actual production line such as coating of a plastic bottle, it is required to repeatedly use the heating element. When the heating element is repeatedly used more than 10,000 times, for example, there is a problem that the heating element is deformed due to oxidative deterioration, or the catalytic activity of the heating element is lost and a thin film having a high gas barrier property cannot be formed. Therefore, in the first embodiment, the heating element 42 is heated in an atmosphere where the inside of the vacuum chamber 31 is appropriately filled with the silicon-containing hydrocarbon gas, so that the oxidation deterioration of the heating element 42 can be suppressed. As a result, even when the heating element is repeatedly used more than 10,000 times, for example, the heating element 42 can be prevented from being deformed due to oxidative degradation.

FIG. 3 is a conceptual diagram showing an example of a pressure change in the vacuum chamber and a temperature change of the heating element in the manufacturing method according to the present embodiment. In the method for manufacturing a gas barrier plastic molded body according to the first embodiment, as shown in FIG. 3, in the preparation process, after adjusting the pressure in the vacuum chamber 31 to P _0, the pressure in the vacuum chamber 31 from P ₀ to reach a higher pressure P _a, in the film formation step, it is preferable to bring the pressure in the vacuum chamber 31 to a high pressure P _B from P _a. A gas barrier thin film having high transparency and high gas barrier properties can be formed.

In the method for producing a gas barrier plastic molded article according to the first embodiment, it is preferable that (P _B -P _A ) / P ₀ is 0.11 or more. More preferably, it is 0.15 or more. A gas barrier thin film having high transparency and high gas barrier properties can be formed. The upper limit of (P _B -P _A ) / P ₀ is not particularly limited, but is preferably 0.67 or less, and more preferably 0.34 or less.

Pressure

_P 0, _{P A} and _{P B} is the pressure detected by the pressure detection unit 80. The pressure detector 80 is preferably provided in the lower chamber port part P as shown in FIG.

When a thin film having a predetermined thickness is formed on the surface of the plastic molded body 4, heating of the heating element 42 is stopped, and the obtained gas barrier plastic molded body is returned to the entrance / exit chamber 32, and then the gate valve 33 is turned on. Close the film forming process.

After the film formation process, the vacuum breaker valve (not shown) installed in the entrance / exit chamber 32 is operated to open the inside / outside chamber 32 to the atmosphere. At this time, it is preferable that the vacuum chamber 31 is always in a vacuum state, and the heating element 42 disposed in the vacuum chamber 31 is always kept in a vacuum state.

Next, the open / close gate 56 is opened, the gas barrier plastic molded body is taken out, and a new untreated plastic molded body is introduced. Then, the open / close gate 56 is closed, and the exhaust process, the preparation process, and the film forming process are repeated.

So far, the method for producing a gas barrier plastic molding having a substantially colorless and transparent gas barrier thin film has been described. However, the gas barrier thin film is not required to have a high degree of transparency (for example, b ^* exceeds 2 and is 6 or less). The case will be described.

The method for producing a gas barrier plastic molded body according to the second embodiment includes an evacuation process in which the inside of the vacuum chamber 31 is evacuated to adjust the inside of the vacuum chamber 31 to an initial pressure P ₀ or less, and the pressure in the vacuum chamber 31 is P. _When the heating element 42 is adjusted to ₀ or less and is not heated, the source gas is introduced into the vacuum chamber 31 to adjust the pressure in the vacuum chamber 31 to P ₀ . A preparatory step, and a film forming step of heating the heating element 42 while continuously introducing the source gas into the vacuum chamber 31 to form a gas barrier thin film on the surface of the plastic molded body 4 accommodated in the vacuum chamber 31. Have.

The manufacturing method according to the second embodiment is different from the manufacturing method according to the first embodiment in the following two points. The first point is the type of the heating element 42. In the first embodiment, the heating element 42 has a tantalum carbide phase, whereas in the second embodiment, the material of the heating element 42 is not limited. The second point is the type of source gas used. While the silicon-containing hydrocarbon gas is used in the first embodiment, the second embodiment is not limited to the silicon-containing hydrocarbon gas. The manufacturing method of the second embodiment has the same basic configuration as the manufacturing method according to the first embodiment except for the above two points. For this reason, here, description is omitted about a common structure, and only a different point is demonstrated.

In the second embodiment, the material of the heating element is not particularly limited, but C, W, Ta, Nb, Ti, Hf, V, Cr, Mo, Mn, Tc, Re, Fe, Ru, Os, Co, Rh , Ir, Ni, Pd and Pt are preferably included. Among these, it is preferable that a heat generating body contains the 1 or 2 or more metal element chosen from the group of Ta, W, Mo, and Nb, for example. The material containing a metal element is a pure metal, an alloy, a metal or alloy containing an additive, or an intermetallic compound. The metal which forms an alloy or an intermetallic compound may be a combination of two or more of the aforementioned metals, or a combination of the aforementioned metals and other metals. The other metal is, for example, chromium. The alloy or intermetallic compound preferably contains a total of 80 atomic% or more of one or more metal elements selected from the group of Ta, W, Mo and Nb. The additive is, for example, an oxide such as zirconia, yttria, calcia, or silica. The addition amount of the additive is preferably 1% by mass or less.

In the second embodiment, the source gas other than the above-mentioned silicon-containing hydrocarbon gas is, for example, alkane-based gases such as methane, ethane, propane, butane, pentane, or hexane, and alkene-based gases such as ethylene, propylene, or butyne. , Alkadiene gases such as butadiene or pentadiene, alkyne gases such as acetylene or methylacetylene, aromatic hydrocarbon gases such as benzene, toluene, xylene, indene, naphthalene or phenanthrene, cycloalkanes such as cyclopropane or cyclohexane Gas, cycloalkene gas such as cyclobenten or cyclohexene, alcohol gas such as methanol or ethanol, ketone gas such as acetone or methyl ethyl ketone S, or it may be an aldehyde gas such as formaldehyde or acetaldehyde.

Next, examples of the present invention will be described. However, the present invention is not limited to these examples.

(Example 1)
A gas barrier plastic molded body was manufactured using the film forming apparatus shown in FIG. A plastic bottle made of PET (with an internal volume of 500 ml) was used as the plastic molding, vinylsilane as the silicon-containing hydrocarbon gas, and tantalum carbide wire (φ0.5 mm) as the heating element. First, the exhaust process was performed as follows. In the evacuation step, the inside of the vacuum chamber was evacuated and the inside of the vacuum chamber was adjusted to an initial pressure P ₀ = 1.5 Pa or less. Subsequently, the preparatory process was performed as follows. In the preparation process, after opening the gate valve, silicon-containing hydrocarbon gas was introduced into the vacuum chamber to adjust the pressure in the vacuum chamber to P ₀ Pa, and then reached P _A Pa higher than P ₀ Pa. . Further, the plastic bottle was lowered from the entrance / exit chamber, and the heating element and the source gas supply pipe were inserted into the plastic bottle. Next, the film forming process was performed as follows. In the film forming process, heating of the heating element is started while continuing the introduction of the silicon-containing hydrocarbon gas, and the heating is performed up to 2100 to 2200 ° C. When the thin film deposited on the inner surface of the plastic bottle reaches 20 nm, the heating is generated. Body heating stopped. Thereafter, the plastic bottle was returned to the entrance / exit chamber, the gate valve was closed, and the gas supply was stopped. In the film forming process, the pressure in the vacuum chamber was allowed to reach P _B Pa higher than P _A Pa. The pressures P _A and P _{B in} each step were adjusted so that (P _B −P _A ) / P ₀ was 0.16. After the film formation process was completed, the inside of the inlet / outlet chamber was opened to the atmosphere, the resulting gas barrier plastic molded article was taken out, and a new untreated plastic bottle was put in to close the open / close gate. These series of film forming operations were repeated.

(Example 2)
_A gas barrier plastic molded article was produced in the same manner as in Example 1 except that the pressures P _A and P _B in each step were adjusted so that (P _B −P _A ) / P ₀ was 0.15.

(Example 3)
_A gas barrier plastic molded article was produced in the same manner as in Example 1 except that the pressures P _A and P _B in each step were adjusted so that (P _B −P _A ) / P ₀ was 0.11.

(Comparative Example 1)
A gas barrier plastic molded article was prepared in the same manner as in Example 1 except that a tantalum wire (φ0.5 mm) that was not carbonized was used as a heating element, the preparatory process was not performed, and the thickness of the thin film was changed to 36 nm. Manufactured.

(XPS analysis-composition analysis)
The surface of the thin film of the plastic bottle obtained in Example 1 and Comparative Example 1 in the first series of film forming operations was analyzed using an XPS apparatus (model: QUANTERASXM, manufactured by PHI). Table 2 shows the ratio of constituent elements on the surface of the thin film. The conditions of XPS analysis are as follows.
Measurement conditions Excitation X-ray: Al mono
Detection area: 100 μmφ
Extraction angle: 90deg
Detection depth: about 8nm

(XPS analysis-binding energy)
Regarding Example 1 and Comparative Example 1, the surface of the thin film of the plastic bottle obtained in the first series of film forming operations was analyzed under the condition (1) using the XPS apparatus described above. The test piece and analysis conditions were the same as in the composition analysis.

FIG. 4 is a narrow scan spectrum of Si2p obtained by XPS analysis of the thin film surface under the condition (1). (A) is the thin film of Example 1, and (b) is the thin film of Comparative Example 1. As shown in FIG. 4, in Example 1, a main peak was observed at the peak appearance position of the Si—C bond energy, whereas in Comparative Example 1, the main peak was observed at the peak appearance position of the Si—Si bond energy. A peak was observed.

(XPS analysis-depth profile analysis)
Using the above-described XPS apparatus, the depth profile of the thin film of the plastic bottle obtained in the first series of film forming operations was analyzed for Example 1 and Comparative Example 1 while performing argon ion etching. The test piece and analysis conditions were the same as in the composition analysis. Here, when the gas barrier thin film is divided into two equal parts in the depth direction, in Example 1, 10 nm on the opposite side to the plastic molded body is the upper layer, 10 nm on the plastic molded body side is the lower layer, and in Comparative Example 1, the plastic is 18 nm on the side opposite to the molded body was the upper layer, and 18 nm on the plastic molded body side was the lower layer.

FIG. 5 is a depth profile of Example 1. In FIG. 5, since the O and C profiles have one extreme value in each of the upper layer and the lower layer, the O profile having the highest priority is selected, and Si, C, and O at the extreme values of the O profile are selected. The content of was compared. In FIG. 5, the extreme value of the profile of O has a minimum value in Sputter Time 1.5 min included in the upper layer, and has a maximum value in Sputter Time 6.0 min included in the lower layer. In Example 1, as shown in FIG. 5, the C content in Sputter Time 1.5 min was higher than the Si content in Sputter Time 1.5 min. Further, in Example 1, as shown in FIG. 5, the O content in Sputter Time 1.5 min was lower than the Si content in Sputter Time 1.5 min. From the above, in Example 1, it was confirmed that the composition at the extreme value of the O profile of the upper layer had the highest C content, followed by the Si content and the O content.

FIG. 6 is a depth profile of Comparative Example 1. In FIG. 6, since the O and C profiles have one extreme value in each of the upper layer and the lower layer, the O profile having the highest priority is selected and Si, C, and O at the extreme values of the O profile are selected. The content of was compared. In FIG. 6, the extreme value of the profile of O has a minimum value in Sputter Time 6.0 min included in the upper layer, and has a maximum value in Sputter Time 13.5 min included in the lower layer. In Comparative Example 1, as shown in FIG. 6, the C content in Sputter Time 6.0 min was lower than the Si content in Sputter Time 6.0 min. In Comparative Example 1, as shown in FIG. 6, the O content in Sputter Time 6.0 min was lower than the Si content in Sputter Time 6.0 min. From the above, in Comparative Example 1, it was confirmed that the composition at the extreme value of the O profile of the upper layer had the highest Si content.

In FIG. 5, when the integrated value of each atomic concentration of Si, C and O in the upper layer was determined, in Example 1, the upper layer had the highest C content, and then the Si content and O content. It could be confirmed. Moreover, in FIG. 6, when the integrated value of each atomic concentration of Si, C, and O in the upper layer was determined, in Comparative Example 1, the upper layer had the highest Si content, followed by the C content and the O content. I was able to confirm.

Further, in Example 1, as shown in FIG. 5, the C content in Sputter Time 6.0 min is higher than the Si content in Sputter Time 6.0 min, and the O content in Sputter Time 6.0 min is Sputter Time 6.0 min. It was higher than the Si content in. On the other hand, in Comparative Example 1, as shown in FIG. 6, the C content in Sputter Time 13.5 min is lower than the Si content in Sutter Time 13.5 min, and the O content in Sputter Time 13.5 min is Sputter. It was higher than the Si content in Time 13.5 min.

In FIG. 5, when the integrated value of each atomic concentration of Si, C, and O in the lower layer was determined, in Example 1, the lower layer had the highest C content, and then the O content and the Si content. It could be confirmed. Moreover, in FIG. 6, when the integrated value of each atomic concentration of Si, C, and O in the lower layer was obtained, in Comparative Example 1, the lower layer had the highest O content, followed by the Si content and the C content. I was able to confirm.

(Transparency evaluation)
The transparency was evaluated using the plastic bottles obtained in the first series of film forming operations for Examples and Comparative Examples. Transparency was evaluated by b ^* value. The b ^* value was measured using a self-recording spectrophotometer (U-3900, manufactured by Hitachi) equipped with a 60Φ integrating sphere attachment device (for infrared, visible and near infrared) manufactured by the same company. As the detector, an ultrasensitive photomultiplier tube (R928: for ultraviolet and visible) and cooled PbS (for near infrared region) were used. The transmittance was measured in the measurement wavelength range of 380 nm to 780 nm. By measuring the transmittance of the PET bottle, the transmittance measurement of only the gas barrier thin film can be calculated. However, the b ^* value in this example is the same as that calculated in the form including the absorption rate of the PET bottle. Show. The test piece used for the measurement of glossiness was used for the measurement. The average value of 3 sheets is shown in Table 3 as b ^* value.

(Gas barrier property evaluation)
Regarding Examples and Comparative Examples, gas barrier properties were evaluated using each plastic bottle obtained when the number of repetitions of a series of film forming operations was 1st, 100th, and 200th. The gas barrier property was evaluated by BIF. First, oxygen permeability was measured for each plastic bottle of the example or comparative example. The oxygen permeability was measured under the conditions of 23 ° C. and 90% RH using an oxygen permeability measuring device (model: Oxtran 2/20, manufactured by Modern Control), conditioned for 24 hours from the start of measurement, and then started measurement. The value after 72 hours had passed. In BIF, in Equation 5, the oxygen permeability value of the unformed film bottle is defined as the oxygen permeability value of the plastic molded body where the thin film is not formed, and the oxygen permeability value of each plastic bottle of the example or comparative example is used as the gas barrier plastic molding. Calculated as oxygen permeability of the body. The evaluation criteria are as follows. The evaluation results are shown in Table 3.
A: BIF of each plastic bottle is 10 or more (practical level).
○: BIF of each plastic bottle is 5 or more and less than 10 (practical lower limit level).
X: BIF of each plastic bottle is less than 5 (practical unsuitable level).

(Mechanical durability evaluation)
After a series of film forming operations was repeated 10,000 times, the heating element was removed from the film forming apparatus, and a 40 to 80 mm portion from the return portion was grasped with a finger, and the strength was confirmed. The evaluation criteria are as follows. The evaluation results are shown in Table 3.
◯: The heating element straight line portion maintains a range of ± 1.5 mm and does not break even when gripped with a finger (practical level).
(Triangle | delta): A heating-element linear part maintains the range of +/- 3.0mm, and even if it hold | grips with a finger, it does not break (practical use lower limit level).
X: The heating element linear portion exceeds the range of ± 3.0 mm and is damaged by finger grip (practical unsuitable level).

As shown in Table 3, each Example was substantially colorless and transparent and had high gas barrier properties. Moreover, compared with the comparative example 1, it has confirmed that it was a manufacturing method excellent in durability with respect to the catalyst activity and intensity | strength of a heat generating body. In particular, Example 1 and Example 2 were able to form a thin film having a high gas barrier property without losing the catalytic activity of the heating element even when the heating element was repeatedly used 10,000 times or more. In each example, (P _B -P _A ) / P ₀ was 0.11 or more, and a gas barrier thin film having high transparency and high gas barrier properties could be formed. In Examples 1 and 2, (P _B -P _A ) / P ₀ was 0.15 or more, and the gas barrier property was kept high even when the heating element was repeatedly used.

4 Plastic molded body (plastic bottle)
31 Deposition chamber (vacuum chamber)
32 Entrance / exit chamber 33 Gate valve 42 Heating element 56 Opening / closing gate 80 Pressure detector VP1 Vacuum pump VP2 Vacuum pump 90 Gas barrier plastic molded body 91 Plastic molded body 92 Gas barrier thin film

92a Upper layer

92b Lower layer 92s Surface of the gas barrier thin film

Claims

In a gas barrier plastic molded body comprising a plastic molded body and a gas barrier thin film provided on the surface of the plastic molded body,
The gas barrier thin film contains silicon (Si), carbon (C), and oxygen (O) as constituent elements, and when the X-ray electron spectroscopic analysis is performed under the condition (1), the peak appearance position of the bond energy of Si—C And a gas barrier plastic molded article having a region where a main peak is observed.
Condition (1) The measurement range is 95 to 105 eV.
The gas barrier thin film has a gradient composition in the depth direction,
When the gas barrier thin film is bisected in the depth direction, the side opposite to the plastic molded body is the upper layer, and the plastic molded body side is the lower layer,
2. The gas barrier plastic molded article according to claim 1, wherein the C content represented by (Equation 1) in the upper layer is higher than the Si content represented by (Equation 2) in the upper layer.
(Equation 1) C content [%] = {(C content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 1, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.
(Expression 2) Si content [%] = {(Si content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Formula 2, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.
3. The gas barrier plastic molded article according to claim 2, wherein an O content represented by (Equation 3) in the upper layer is lower than an Si content in the upper layer.
(Equation 3) O content [%] = {(O content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 3, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.
The gas barrier thin film has a gradient composition in the depth direction,
When the gas barrier thin film is bisected in the depth direction, the side opposite to the plastic molded body is the upper layer, and the plastic molded body side is the lower layer,
4. The C content represented by (Equation 1) in the lower layer is higher than the O content represented by (Equation 3) in the lower layer. Gas barrier plastic molding.
(Equation 1) C content [%] = {(C content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 1, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.
(Equation 3) O content [%] = {(O content [atomic%]) / (total content of Si, O and C [atomic%])} × 100
In Equation 3, the content of Si, O, or C is the content in the breakdown of the three elements of Si, O, and C.
Evacuating the inside of the vacuum chamber to adjust the inside of the vacuum chamber to an initial pressure P 0 or less;
Silicon-containing hydrocarbon gas is introduced into the vacuum chamber when the pressure in the vacuum chamber is adjusted to P 0 or less and the heating element having a tantalum carbide phase disposed in the vacuum chamber is not heated. A preparatory step of adjusting the pressure in the vacuum chamber to the P 0 ,
A film forming step of heating the heating element while continuously introducing the silicon-containing hydrocarbon gas into the vacuum chamber to form a gas barrier thin film on the surface of the plastic molded body housed in the vacuum chamber;
A method for producing a gas barrier plastic molded article, comprising:
In the preparation step, wherein after adjusting the pressure in the vacuum chamber to said P 0, to reach the pressure of the vacuum chamber at a higher pressure P A from the P 0,
Wherein in the film forming step, the manufacturing method of the gas barrier plastic molded body according to claim 5, characterized in that to reach the pressure of said vacuum chamber to said P A higher pressures P B.
7. The method for producing a gas barrier plastic molded article according to claim 6, wherein (P B -P A ) / P 0 is 0.11 or more.